How to extend the general Page functionality in EPiServer CMS 5

Still being a newbie in the EPiServer company I learn a lot of new things every day - both about the product and the company.

I've decided to share some of my discoveries here - perhaps they help other EPiServer newbies out there :-)

Today I came across quite a useful, but not-so-well-documented feature in EPiServer CMS 5: The ability to extend the general functionality of your Pages. So, if for instance you want to add a piece of code that should be executed whenever a page is shown, and which can affect that page, but don't feel like inheriting the TemplatePage type and letting all your pages inherit from your custom type, there is actually quite a neat way of doing it.

The trick is the PagePlugIn attribute. You can create a class, put the PagePlugIn attribute (from the EPiServer.PlugIn namespace) and add static method with the signature void Initialize(int) and from that method setup an event handler to handle the EPiServer.PageBase.PageSetup event.

Here's an example on how you can use this functionality to add an extra menu item to the context menu:

   [PagePlugIn]
   public class MyPagePlugin
   {

       public static void Initialize(int bitflags)
       {
           EPiServer.PageBase.PageSetup += new EPiServer.PageSetupEventHandler(PageBase_PageSetup);           
       }

       static void PageBase_PageSetup(EPiServer.PageBase sender, EPiServer.PageSetupEventArgs e)
       {
           sender.ClientScript.RegisterClientScriptInclude("OnScript", "MyScript.js");
           sender.PreRender += new EventHandler(sender_PreRender);
       }

       static void sender_PreRender(object sender, EventArgs e)
       {
           (sender as EPiServer.PageBase).ContextMenu.Menu.Add("MyItem", EPiServer.Security.AccessLevel.Edit, new EPiServer.RightClickMenuItem("My Script", "MyScript()", "MyScriptSubMenu"));
       }

   }